As western forests dry, trees become weakened and, as Olsen says, are "sitting ducks" for outbreaks of voracious mountain beetles. If lack of moisture doesn't kill trees, insects will, leaving forests with dead needs temporarily more susceptible to burning.  Photo of national forest in Colorado courtesy USDA
As western forests dry, trees become weakened and, as Olsen says, are "sitting ducks" for outbreaks of voracious mountain beetles. If lack of moisture doesn't kill trees, insects will, leaving forests with dead needs temporarily more susceptible to burning. Photo of national forest in Colorado courtesy USDA